Ruak, who is 62 years old, said he will leave Timor-Leste on 16 June, and that Hermenegildo Pereira, the State President and Council Minister, would stand in as interim Prime Minister during his absence.

Ruak did not say how serious his condition was but added that he “did not know” when he would return to Timor-Leste.

“When my health improves I will return home,” Ruak said.

Details of the illness are still scarce. The announcement comes amid heightened pressure on the Prime Minister to resolve government structure and political uncertainty.